It is common practice to actuate various downhole tools in a wellbore by pressuring up from the surface to effect the actuation. In some cases a ball seat and ball are used to shut off the bore downhole of a tool that is to be actuated. This enables the operator to pressure up on the portion of the well uphole of the ball and seat, thereby effecting the pressure actuation of the target tool. After the tool has been actuated it may be desirable to reopen the bore where the ball and seat are located so as not to obstruct production flow from the well, for example.
Systems have been developed in which a deformable ball such as an elastomeric ball, for example, is dropped onto a seat for the actuation and then can be pushed through the seat upon an increase in the hydraulic pressure from above. In order to accomplish this result the ball is deformed. The ball must therefore be carefully engineered to hold pressure at a level calculated to facilitate the desired actuation and then deform at a selected higher pressure deliverable selectively from uphole. Once the ball is through the seat it can fall to the bottom of the wellbore, for example, leaving the seat inside dimension open. In such cases, however, the restricted diameter seat, upon which the ball was seated, remains in the wellbore forming a diametrical restriction in the wellbore that can have a detrimental affect on subsequent operations or, for example, production flows. It would, therefore, be desirable in the art to have a system allowing the simple removal of all restrictions in the wellbore subsequent to actuation of a tool.